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Migration Guide

From v2 to v3

The changes made going from v2 to v3 were:

  • Removal of the Hydrator subcomponent.
  • Removal of the CallbackHandler class.
  • Removal of Zend\Stdlib\Guard\GuardUtils.


The biggest single change from version 2 to version 3 is that the hydrator subcomponent, which was deprecated in v2.7.0, is now removed. This means that if you were using zend-stdlib principally for the hydrators, you need to convert your code to use zend-hydrator.

This will also mean a multi-step migration. zend-stdlib v3 pre-dates zend-hydrator v2.1, which will be the first version that supports zend-stdlib v3 and zend-servicemanager v3. If you are using Composer, the migration should be seamless:

  • Remove your zend-stdlib dependency:
  $ composer remove zendframework/zend-stdlib
  • Update to use zend-hydrator:
  $ composer require zendframework/zend-hydrator

When zend-hydrator updates to newer versions of zend-stdlib and zend-servicemanager, you will either automatically get those versions, or you can tell composer to use those specific versions:

$ composer require "zendframework/zend-stdlib:^3.0"


Zend\Stdlib\CallbackHandler primarily existed for legacy purposes; it was created before the callable typehint existed, so that we could typehint PHP callables. It also provided some minimal features around lazy-loading callables from instantiable classes, but these features were rarely used, and better approaches already exist for handling such functinality in zend-servicemanager and zend-expressive.

As such, the class was marked deprecated in v2.7.0, and removed for v3.0.0.


Version 3 removes Zend\Stdlib\Guard\GuardUtils. This abstract class existed to provide the functionality of the various traits also present in that subcomponent, for consumers on versions of PHP earlier than 5.4. Since the minimum required version is now PHP 5.5, the class is unnecessary. If you were using it previously, compose the related traits instead.

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